1. Field of the Invention
The present invention relates to a method and a device for making a coffee beverage of a high grade and low caffeine.
2. Related Arts
Coffee is known as the premier beverage around the world, has strong culture, and is one of indispensable beverages in people's social activities, such as relaxation, business talks, or meeting friends. Although various methods for making a coffee beverage exist, a rich aroma and acid, bitter, astringency, and sweet of the coffee are burned into the memories.
In a cup of high-grade coffee beverage, a main source of the aroma is volatile fat in the coffee. Conventional methods for making a coffee beverage include a hot water filtering method, a cooking method, and a high pressure filtering method. The main purpose of the methods is to extract as many aromas in the coffee as possible. The aroma in the coffee comes from volatile fat in coffee beans. In order to obtain the fat, people have to adjust a water temperature in making the coffee beverage, so as to adapt to extraction of the volatile fat of the coffee. However, a high water temperature enables a part of the volatile fat to volatilize and not to be effectively used, and an excessively high water temperature enables the coffee to be over-extracted, so that the coffee tastes different. Therefore, how to select a water temperature and a pressure is always a puzzle in making the coffee. A volatile component and a water-soluble component are extracted by a single method, so the relationship between the both components needs to be balanced, and the extraction of the volatile component and the water-soluble component needs to be traded off for each other. In this way, a balance result is generally as follows. Since partial components in the coffee generate an abnormal taste, in the conventional method, excessively high temperature and excessively much time are generally rejected to prevent over-extraction and generation of the abnormal taste. Therefore, extraction of the fat mainly contributing to the aroma of the coffee is affected.
In another aspect, a big contradiction between the chase for health and drinking of the coffee exists for modern people. The harm of caffeine in the coffee to health is gradually known by people. As published by the world health organization, a maximum intake of the caffeine cannot exceed 300 mg per day and per adult. However, a person drinks 3 to 4 cups of coffee each day, and the normal content of the caffeine in each cup of coffee beverage is generally 100 to 150 mg, so the daily intake reaches more than 400 mg or even is up to twice a secure amount.
To this end, for health, people process the coffee beans and remove the caffeine in the beans through different methods. However, in the removing process, some components having other tastes and aroma in the coffee are unavoidably removed, so that the quality of the coffee is decreased. Nowadays, the coffee culture is very abundant, so this kind of coffee bean cannot satisfy the requirements of the consumers.